President Trump’s surprise decision to rapidly withdraw all U.S. troops from Syria is meeting with intense criticism by foreign policy experts, who denounce it as strategically stupid, reckless for national security and a blow to America’s global credibility. But inside Syria, the consequences are even more serious. For one example, 50,000 Syrian civilian refugees living under the direct protection of the U.S. military are suddenly fearing for their lives.

For three years, civilians living in the Rukban refugee camp in the southeastern Syrian desert have survived because of the protection of U.S. forces encamped 10 miles away on a base called Tanf. The refugee camp falls within Tanf’s 55-kilometer-radius security zone. The residents rely on the United States to protect them from the Syrian regime and Iranian forces and to ensure vital flows of humanitarian aid.

They are near starvation, effectively under siege and living in squalor. But despite their situation, they will tell anyone who will listen that they are grateful to be free from the grasp of Syrian President Bashar al-Assad and that they are depending on the United States to keep them safe and alive. On Wednesday, Trump put their lives at grave risk with a single tweet.

“Our reaction is extreme worry and fear by all those living in the camp,” Abu Hussein Al Homsie, a resident of the refugee camp, told me. “We used to think that the American soldiers were here for us, in order to save us from Iran and Assad and to provide us security. . . . Unfortunately, we were mistaken.”

Just last week, Al Homsie told me that the refugees were living “under the protection of God and the American base.” Today, they have zero information on what happens when U.S. troops leave. “We have no idea what our fate is now,” he said.

The Assad regime and its partners have been trying to push the United States out of the strategically important area. Tanf is the last outpost preventing Assad from retaking the entire region (and Iran from completing its planned “land bridge” from Tehran to the Mediterranean). There’s no doubt that when U.S. forces withdraw, Assad’s army, aided by Iranian militias and Russian air power, will conquer the area by force.

The refugees, internally displaced Sunni Arabs, have spent almost eight years resisting Assad’s rule. Anyone in the camp who comes under any suspicion will face torture and murder. Local partners trained and equipped by the United States will be forced to switch sides or die.

It’s not a guess. Wherever Assad has retaken liberated areas, he has punished those civilians with mass torture and mass murder as well as hunting down anyone who ever worked with the United States, such as the rescue workers known as the White Helmets.

“We are sending them to their slaughter,” said Mouaz Moustafa, executive director of the Syrian Emergency Task Force, a U.S. nongovernmental organization that works with the Syrian opposition. “We are handing over our partner forces alongside these civilians to a regime that has no mercy.”

What’s even more tragic is that the U.S. government was in the middle of negotiations with the Russians over of the fate of the Rukban camp when Trump announced his new policy. At an event Monday, James Jeffrey, the State Department’s special representative for Syria engagement, said that the United Nations was about to circulate a new plan to set conditions for the next aid convoy, which has already been delayed.

Russia says aid convoys can’t go into the camp because the U.S. partner forces there are “terrorists.” Jeffrey called that nonsense and said Russia was using the aid to try to force the United States out of the area. He apparently didn’t know Trump would do Moscow’s work for it.

“Basically this is a lack of Russian cooperation,” Jeffrey said. “We consider this a totally political move to try to squeeze us in another area where the Russians claim that we are illegitimately and illegally present.”

While holding back aid convoys under the guise of security concerns, the Russian military is telling reporters that the United States is intentionally starving these refugees to recruit them into becoming “terrorists.” It’s all part of the Russian government’s disinformation campaign, which casts the United States as illegal occupiers inside Syria and as the cause of the humanitarian crisis.

But despite all their lies, the Russians were trying to negotiate. Even if Trump was intent on withdrawing, he could have bargained for concessions that would have protected U.S. security interests and provided for the Syrian civilians we are leaving behind. Instead, Trump gave it all away for free — and left the people in the Rukban camp with nothing but fear.

When the Assad regime and Iran take over eastern Syria, the United States will realize it has made a long-term strategic blunder. But in the shorter term, millions of Syrians will suffer. The Assad regime, Russia and Iran are their killers, but Trump’s tweet sealed their fate.

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Josh RoginJosh Rogin is a columnist for the Global Opinions section of The Washington Post. He writes about foreign policy and national security. Rogin is also a political analyst for CNN. He previously worked for Bloomberg View, the Daily Beast, Foreign Policy, Congressional Quarterly, Federal Computer Week and Japan's Asahi Shimbun newspaper. Follow